1. Field of the Invention
The present invention provides for a novel nutraceutical formulation comprising an extract of the root zingiber zerumbet Sm, and the use of the same to regulate the immune system.
2. Description of the Related Art
Leukotrienes (LT), specifically the cysteinyl LTs, LTC4, LTD4 and LTE4, have been implicated in the clinical course, physiologic changes, and pathogenesis of asthma (1). LTC4, LTD4 and LTE4 are potent bronchoconstrictors and involve in additional effects on blood vessels, mucociliary clearance and eosinophilic inflammation (2). In addition, the cysteinyl LTs are formed from cells commonly associated with asthma, including eosinophils and mast cells (3). Therefore, leukotriene receptor antagonists are being used widely in the treatment of bronchial asthma. However, the published data regarding liver injury related to a novel group of asthma drugs, typically leukotriene receptor antagonists, are in heightened awareness of hepatotoxicity (4). Thus, herbs open a new window for having medicative potential on long-term therapy of asthma. The Th cell cytokines by peripheral blood T cells have been found to correlate with asthma severity. Recent research showed that interleukin-4□IL-4□binding to its receptor (IL-4R) is essential for the development of airway inflammation present in asthma (5). A significantly lower ratio of IFN-gamma-/lL-4-producing CD4+ T cells after 12-O-tetradecanoylphorbol-13-acetate (TPA)/ionomycin stimulation was found in patients with atopic cough and atopic asthma compared with normal subjects, and the proportion of IL-4-producing CD4+ T cells was significantly higher in patients with atopic asthma than in normal control subjects (6). As compared with control human subjects, acute asthmatics had significantly increased levels of circulating IL-4 (p<0.001), IL-5 (p<0.001), and IL-13 (p<0.001), although the differences were of borderline significance in serum IFN-gamma (p=0.069) (7). However, the extremely low serum levels of these cytokines were merely detectable in animal studies. A new cheap biotech examination, quantitative competitive reverse transcriptase-polymerase chain reaction (qc-RT-PCR), was therefore developed in our lab to quantify gene expressions of cytokines in immune cells in order to precisely evaluate the therapeutic indications of traditional herbs. As searching potential medicative herb, competitive cysteinyl leukotriene receptor antagonist has been considered as a new class of asthma medications (8). Zingiber zerumbet Smith has recently been found to have anti-tumor promoter activity (9) and markedly diminished inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), together with the release of tumor necrosis factor-alpha (TNF-α) in mouse macrophages (10).